It is becoming clear that cancer and subsequent treatment impact cognitive function. These deficits may result either from pathological changes due to cancer itself, the treatment program, or both. Despite the prevalence of cognitive symptoms, it is currently difficult to accurately assess the symptoms for a number of reasons. Specifically, existing ?gold standard? assessments often lack sensitivity to many cancer related deficits, cannot be repeated and thus cannot be used for monitoring of cognitive change, and are generally disconnected from the cognitive psychology and neuroscience tasks that inform our current mechanistic understanding of cognitive function. We have developed a mobile platform for collecting cognitive and behavioral data that overcomes the issues noted above. In the current proposal, our objective are to 1) develop a cancer-?specific cognitive assessment tool that can be used with minimal supervision inside or outside of a clinic, 2) develop a clinician dashboard that provides access to data collected through the platform, and 3) perform comprehensive usability testing of the prototype product with a group of clinicians and patients with cancer. The ultimate goal will be to develop a fully functional prototype assessment tool that can be used in comprehensive validation studies in Phase II.